I edited the photo Paul. If you copy the whole image tag from your gallery it will be a thumb nail. Here's the whole thing from one of my photos (I have modified it so that it doesn't actually work but you can see what it is).

You don't actually need all of that but it works, clearly. I never knew that! One is the image URL it wraps around the [img ] tag [URL] at the beginning and at the end [URL]:

Although you have proven that it can stay, here is the image tag on its own, again modified to stop it posting the photo:

[imghttps://gallery3.kitmaker.net/data/30465/ thumbs/06821.jpg[/img

Note: If when you copy the tag you miss a bit, say one of the end brackets, it won't be recognised for what it is. Similarly you can modify it and in this case notice the "thumbs/" and it is this part that need removing to make the image full sized in your post. Also note that you need to remove one of the /, either the one in front or the one after "thumbs". If you leave both, or remove both it won't be recognised for an image tag.